diff --git a/src/go/types/check_test.go b/src/go/types/check_test.go
index fb18ac87d2..2bdfc150f4 100644
--- a/src/go/types/check_test.go
+++ b/src/go/types/check_test.go
@@ -91,6 +91,7 @@ var tests = [][]string{
 	{"testdata/issues.src"},
 	{"testdata/blank.src"},
 	{"testdata/issue25008b.src", "testdata/issue25008a.src"}, // order (b before a) is crucial!
+	{"testdata/issue26390.src"},                              // stand-alone test to ensure case is triggered
 }
 
 var fset = token.NewFileSet()
diff --git a/src/go/types/decl.go b/src/go/types/decl.go
index cabf989027..11b68583e3 100644
--- a/src/go/types/decl.go
+++ b/src/go/types/decl.go
@@ -165,6 +165,31 @@ func (check *Checker) objDecl(obj Object, def *Named, path []*TypeName) {
 			}
 
 		case *TypeName:
+			// fixFor26390 enables a temporary work-around to handle alias type names
+			// that have not been given a type yet even though the underlying type
+			// is already known. See testdata/issue26390.src for a simple example.
+			// Set this flag to false to disable this code quickly (and comment
+			// out the new test in decls4.src that will fail again).
+			// TODO(gri) remove this for Go 1.12 in favor of a more comprehensive fix
+			const fixFor26390 = true
+			if fixFor26390 {
+				// If we have a package-level alias type name that has not been
+				// given a type yet but the underlying type is a type name that
+				// has been given a type already, don't report a cycle but use
+				// the underlying type name's type instead. The cycle shouldn't
+				// exist in the first place in this case and is due to the way
+				// methods are type-checked at the moment. See also the comment
+				// at the end of Checker.typeDecl below.
+				if d := check.objMap[obj]; d != nil && d.alias && obj.typ == Typ[Invalid] {
+					// If we can find the underlying type name syntactically
+					// and it has a type, use that type.
+					if tname := check.resolveBaseTypeName(ast.NewIdent(obj.name)); tname != nil && tname.typ != nil {
+						obj.typ = tname.typ
+						break
+					}
+				}
+			}
+
 			if useCycleMarking && check.typeCycle(obj) {
 				// break cycle
 				// (without this, calling underlying()
diff --git a/src/go/types/testdata/issue26390.src b/src/go/types/testdata/issue26390.src
new file mode 100644
index 0000000000..b8e67e9bdd
--- /dev/null
+++ b/src/go/types/testdata/issue26390.src
@@ -0,0 +1,11 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue26390
+
+type A = T
+
+func (t *T) m() *A { return t }
+
+type T struct{}